Multielectrode Cortical Stimulation Selectively Induces Unidirectional Wave Propagation of Excitatory Neuronal Activity in Biophysical Neural Model

Cortical stimulation is emerging as an experimental tool in basic research and a promising therapy for a range of neuro-psychiatric conditions. As multielectrode arrays enter clinical practice, the possibility of using spatiotemporal patterns of elec-trical stimulation to induce desired physiological patterns has become theoretically possible, but in practice can only be implemented by trial-and-error because of a lack of predictive models. Experimental evidence increasingly establishes travel-ing waves as fundamental to cortical information-processing, but we lack an understanding of how to control wave properties despite rapidly improving technologies. This study uses a hybrid biophysical-anatomical and neural-computational model to predict and understand how a simple pattern of cortical surface stimulation could induce directional traveling waves via asymmetric activation of inhibitory interneurons. We found that pyramidal cells and basket cells are highly activated by the anodal electrode and minimally activated by the cathodal electrodes, while Martinotti cells are moderately activated by both electrodes but exhibit a slight preference for cathodal stimulation. Network model simulations found that this asymmetrical activation results in a traveling wave in superficial excitatory cells that propagates unidirectionally away from the electrode array. Our study reveals how asymmetric electrical stimulation can easily facilitate traveling waves by relying on two distinct types of inhibitory interneuron activity to shape and sustain the spatiotemporal dynamics of endogenous local circuit mechanisms.

Automated summary

Cortical stimulation is a useful tool for research and treatment of neuro-psychiatric conditions, but the lack of predictive models makes it difficult to control the induced physiological patterns. This study uses a hybrid model to understand how cortical surface stimulation can induce traveling waves through asymmetrical activation of inhibitory interneurons. The results show that asymmetric electrical stimulation can easily facilitate traveling waves by relying on the activation of different types of inhibitory interneurons.